EncodedAppenderWriter.java

/*
 * Copyright 2013 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.grails.encoder;

import java.io.IOException;
import java.io.Writer;

/**
 * A java.io.Writer implementation that writes to a {@link EncodedAppender} with
 * a certain encoder
 * 
 * This class isn't thread-safe.
 *
 * @author Lari Hotari
 * @since 2.3
 */
public class EncodedAppenderWriter extends Writer implements EncodedAppenderWriterFactory, EncodedAppenderFactory, EncoderAware {
    protected EncodedAppender encodedAppender;
    protected Encoder encoder;
    protected EncodingStateRegistry encodingStateRegistry;
    private char[] singleCharBuffer=new char[1];

    /**
     * Default constructor
     *
     * @param encodedAppender
     *            the EncodedAppender destination
     * @param encoder
     *            the encoder to use
     * @param encodingStateRegistry
     *            the {@link EncodingStateRegistry} to use to lookup encoding
     *            state of CharSequence instances
     */
    public EncodedAppenderWriter(EncodedAppender encodedAppender, Encoder encoder,
            EncodingStateRegistry encodingStateRegistry) {
        this.encodedAppender = encodedAppender;
        this.encoder = encoder;
        this.encodingStateRegistry = encodingStateRegistry;
    }

    /*
     * (non-Javadoc)
     * @see java.io.Writer#write(char[], int, int)
     */
    @Override
    public void write(char[] cbuf, int off, int len) throws IOException {
        encodedAppender.append(encoder, null, cbuf, off, len);
    }

    /*
     * (non-Javadoc)
     * @see java.io.Writer#flush()
     */
    @Override
    public void flush() throws IOException {
        encodedAppender.flush();
    }

    /*
     * (non-Javadoc)
     * @see java.io.Writer#close()
     */
    @Override
    public void close() throws IOException {
        encodedAppender.close();
    }

    /*
     * (non-Javadoc)
     * @see java.io.Writer#write(int)
     */
    @Override
    public void write(int c) throws IOException {
        append((char)c);
    }

    /*
     * (non-Javadoc)
     * @see java.io.Writer#write(java.lang.String, int, int)
     */
    @Override
    public void write(String str, int off, int len) throws IOException {
        encodedAppender.append(
                encoder,
                (encodingStateRegistry != null && off == 0 && len == str.length()) ? encodingStateRegistry
                        .getEncodingStateFor(str) : null, str, off, len);
    }

    /*
     * (non-Javadoc)
     * @see java.io.Writer#append(java.lang.CharSequence)
     */
    @Override
    public Writer append(CharSequence csq) throws IOException {
        encodedAppender.append(encoder,
                (encodingStateRegistry != null) ? encodingStateRegistry.getEncodingStateFor(csq) : null, csq, 0,
                csq.length());
        return this;
    }

    /*
     * (non-Javadoc)
     * @see java.io.Writer#append(java.lang.CharSequence, int, int)
     */
    @Override
    public Writer append(CharSequence csq, int start, int end) throws IOException {
        encodedAppender.append(encoder, null, csq, 0, end - start);
        return this;
    }

    /*
     * (non-Javadoc)
     * @see java.io.Writer#append(char)
     */
    @Override
    public Writer append(char c) throws IOException {
        singleCharBuffer[0]=(char)c;
        encodedAppender.append(encoder, null, singleCharBuffer, 0, 1);
        return this;
    }

    /*
     * (non-Javadoc)
     * @see EncodedAppenderFactory#
     * getEncodedAppender()
     */
    public EncodedAppender getEncodedAppender() {
        return encodedAppender;
    }

    /*
     * (non-Javadoc)
     * @see
     * EncoderAware#getEncoder()
     */
    public Encoder getEncoder() {
        return encoder;
    }

    /*
     * (non-Javadoc)
     * @see
     * EncodedAppenderWriterFactory
     * #getWriterForEncoder(Encoder,
     * EncodingStateRegistry)
     */
    public Writer getWriterForEncoder(Encoder encoder, EncodingStateRegistry encodingStateRegistry) {
        return new EncodedAppenderWriter(encodedAppender, encoder, encodingStateRegistry);
    }
}